20XE Omex limiter

[Iain]

I have an OMEX limiter for a 20XE engine running standard early injection (FP ecu, no lambda, coil and dizzy setup)

Fitted an OMEX single coil rev limiter, set it at the desired RPM, and it feels like I'm driving into a brick wall when it hits the limiter. As if it lets me rev beyond that then cuts it for far too long to bring the RPM down.

It has a second lower limiter operated by a button, which also feels very harsh. Weirdly I can drive through this by putting my foot down on the throttle more.

Something is definitely working wrong. Any ideas what is going on or what I've done?

[chimp007_uk]

Sounds like a hard limiter? The micro dynamics one I was running till I went to megajolt was a hard cut, I wired in a "launch" function too.

[Iain]

Does that even when you set it to 'soft limit'. It doesn't just cap it, it throws the front of the car down violently and pops through the exhaust or inlet, I can't tell which.

Same for the launch, which makes it completely unusable as launch, so something is definitely wrong.

[Dave A]

I have just fitted the same Omex unit to my rallycar and I am having exactly the same issue. Plus it doesnt even seem to be consistent at the point it cuts in. Its so bad I am considering taking it off and relying on the rev counter again, sounds like turbo with anti lag on!!

[chambers1984]

i had the same with mine about 12 month ago its sat in bottom of my toolbox since was a big waste of time and money

[chimp007_uk]

Does sound like some fundamental issues somewhere... Weird that everyone has the same issues? Is there not a conflict with the standard ECU limiter?

Mine was running on carbs. Mine is a hard cut, and is violent, but not to the point that car is un-driveable. On launch, it splits and bangs and flames out the exhaust due to the excess fuel etc.

[Dave A]

Mines on carbs, so no ecu interference. The soft cut seems to be too narrow before you hit the hard limit, not I was expecting at all. Pops,spits bangs just like a turbo would, but very hard to drive with! Did an autotest on Sunday in mine and kept having to raise the limit as it was cutting in way sooner than it should have done.

[Iain]

Rev limit set just before 3000rpm, soft cut, you can see it bounces very slowly and you can drive through it!??


http://www.youtube.com/watch?v=Zm-FhZDvFa0&feature=youtu.be

[chimp007_uk]

Not quite the same, but this is how it should be.


http://youtu.be/9a217zBdqf8

[Iain]

Exactly what I expected it to be like Chimp. Quite similar to the standard limiter. This seems quite slow 'bounces' cutting more than just one or two sparks at a time.

[chimp007_uk]

This is the one I used, will be going on the Mrs' car.

Link (http://www.ebay.co.uk/itm/Micro-Dynamics-Smoothcut-RL5-Dashtop-Rev-Limiter-/110952115549?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item19d542ed5d)

[Iain]

Looks good but I already have a spanking new OMEX one so fingers crossed I can get it working.

Chatted to the OMEX guys on the phone earlier, very polite and helpful, he's going to watch my video and let me know any suggestions to resolve it.

[Dave A]

I'd be interested to hear what they advise.

[Iain]

I'd suggest talking to them directly incase I mistranslate anything, but so far the suggestions have been:
- Check the unit is earthed well
- Take the +ve from another source that isn't the coil
- Check it's definitely on the right terminal on the coil, and that the coil hasn't been wired back to front, try it on the other terminal on the coil anyway
- There was some mention of ECU interference thinking it was misfiring, however he thought mine was too old for this

Sounds like he's willing to take it back via post for testing to rule out a faulty unit.

[Iain]

Hopefully sorted now, returned the unit back to them and they diagnosed it with a fault which causes it to partially cut. They've sent me out a new one which I'm optimistic about working! Very helpful company and happy to help.